Electronic device with housing storing electronic component

ABSTRACT

According to one embodiment, an electronic device includes a housing with a through-hole, a flexible printed circuit inserted through the through hole and including a first connection portion on an inner side of the housing with first connection pads and a second connection portion on an outer side of the housing with second connection pads, a first electrical component in the housing, and a first connector connected to the first electrical component and including connection terminals contacting the first connection pads. A first pad of the first connection pads is greater than other first connection pads.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2018-174649, filed Sep. 19, 2018, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an electronic device.

BACKGROUND

In general, electronic devices comprise a housing and a plurality ofelectrical components disposed in the housing. The electrical componentsare electrically connected to other electrical components providedoutside the housing via connection mechanisms such as connectors orwiring boards.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an external appearance of a harddisk drive (HDD) according to a first embodiment.

FIG. 2 is an exploded perspective view of the HDD according to the firstembodiment.

FIG. 3 is a perspective view showing a base of a housing of the HDD.

FIG. 4 is an exploded perspective view showing a back surface side ofthe base and a control circuit board.

FIG. 5 is a development view of a flexible printed circuit constitutinga connection structure portion.

FIG. 6 is a perspective view showing the flexible printed circuit and apart of the housing.

FIG. 7 is a perspective view showing the flexible printed circuit and aconnecter disposed in the housing.

FIG. 8 is a sectional view of the housing and the connection structureportion along line A-A of FIG. 3.

FIG. 9A is a plan view schematically showing a connection state of aconnection portion of the flexible printed circuit and a connectordisposed at a predetermined position.

FIG. 9B is a plan view schematically showing a connection state of theconnection portion of the flexible printed circuit and a connectordisposed at a position shifted from the predetermined position.

FIG. 10 is a development view of the flexible printed circuit accordingto a first modified example.

FIG. 11 is a development view of the flexible printed circuit accordingto a second modified example.

FIG. 12 is a development view of the flexible printed circuit accordingto a third modified example.

FIG. 13 is a plan view showing the flexible printed circuit and a partof the housing according to the third modified example.

FIG. 14 is a plan view showing a slit in the housing according to afourth modified example.

FIG. 15 is a plan view showing the slit in the housing according to afifth modified example.

FIG. 16A is a cross sectional view showing a slit in the housingaccording to a sixth modified example.

FIG. 16B is a longitudinal sectional view showing the slit in thehousing according to the sixth modified example.

FIG. 16C is a plane view showing the slit in the housing according tothe sixth modified example.

FIG. 17 is a plan view showing the connection portion of the flexibleprinted circuit according to a seventh modified example.

DETAILED DESCRIPTION

Various embodiments will be described hereinafter with reference to theaccompanying drawings. In general, according to one embodiment, anelectronic device comprises: a housing comprising a through-hole; aflexible printed circuit comprising a first connection portion providedwith a plurality of first connection pads and a second connectionportion provided with a plurality of second connection pads, wherein theflexible printed circuit is inserted in the through-hole, the firstconnection portion is disposed on an inner side of the housing, and thesecond connection portion is disposed on an outer side of the housing; afirst electrical component in the housing; and a first connector in thehousing connected to the first electrical component, the first connectorcomprising a plurality of connection terminals which contact the firstconnection pads, respectively, wherein a first pad of the firstconnection pads is greater than other first connection pads.

The disclosure is merely an example, and proper changes in keeping withthe spirit of the invention, which are easily conceivable by a personwith ordinary skill in the art, come within the scope of the inventionas a matter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc., of therespective parts are illustrated schematically in the drawings, ratherthan as an accurate representation of what is implemented. However, suchschematic illustration is merely exemplary, and in no way restricts theinterpretation of the invention. In addition, in the specification anddrawings, the same elements as those described in connection withpreceding drawings are denoted by like reference numbers, and detaileddescription thereof is omitted unless necessary.

First Embodiment

A hard disk drive (HDD) according to an embodiment will be described indetail as an example of an electronic device.

FIG. 1 is a perspective view showing an external appearance of the HDDaccording to a first embodiment. FIG. 2 is an exploded perspective viewshowing an internal structure of the HDD.

As shown in FIG. 1 and FIG. 2, the HDD comprises a housing 10 which isflat and substantially in the shape of a rectangular parallelepiped. Thehousing 10 comprises a rectangular box-shaped base 12 having an openedtop surface, an inner cover 14 screwed to the base 12 with screws 13 toclose the top opening of the base 12, and an outer cover (top cover) 16overlaid on the inner cover 14 and including a peripheral portion weldedto the base 12. The base 12 comprises a rectangular bottom wall 12 awhich faces the inner cover 14 with a gap therebetween, and sidewalls 12b which stand along a periphery of the bottom wall 12 a. The bottom wall12 a and the sidewalls 12 b are integrally formed of, for example, analuminum alloy. The sidewalls 12 b include a pair of long side wallsfacing each other, and a pair of short side walls facing each other. Asubstantially rectangular frame-shaped fixing rib 12 c is provided ontop surfaces of the sidewalls 12 b.

The inner cover 14 is, for example, formed of stainless steel into theform of a rectangular plate. The inner cover 14 is fixed in the insideof the fixing rib 12 c with its peripheral portion screwed on the uppersurfaces of the sidewalls 12 b of the base 12 with the screws 13. Theouter cover 16 is, for example, formed of aluminum into the form of arectangular plate. The outer cover 16 is formed to have planardimensions slightly greater than those of the inner cover 14. The wholeperipheral portion of the outer cover 16 is welded to the fixing rib 12c of the base 12 and fixed thereto in an airtight manner.

Vents 46 and 48 to communicate the outside and inside of the housing 10with each other are formed in the inner cover 14 and the outer cover 16,respectively. The air in the housing 10 is discharged through the vents46 and 48 and then a low-density gas (inert gas) having a density lowerthan that of air, for example, helium is introduced through the vents 46and 48 and enclosed or sealed in the housing 10. For example, a seal(sealing member) 50 is stuck on the outer surface of the outer cover 16so as to close the vent 48.

As shown in FIG. 2, in the housing 10, a plurality of magnetic disks 18as recording media, for example, five to nine magnetic disks 18, and aspindle motor 20 as a driving portion which supports and rotates themagnetic disks 18 are provided. The spindle motor 20 is disposed on thebottom wall 12 a. Each of the magnetic disks 18 is, for example, formedto have a diameter of 95 mm (3.5 inches), and comprises a magneticrecording layer in their upper surfaces and/or lower surfaces. Themagnetic disks 18 are fitted to a hub of the spindle motor 20, which isnot shown in the figures, coaxially with each other, and are clamped bya clamp spring and fixed to the hub. Each of the magnetic disks 18 isthereby supported in a state in which each of the magnetic disks 18 islocated parallel to the bottom wall 12 a of the base 12. The magneticdisks 18 are rotated at a predetermined rate of rotation by the spindlemotor 20.

In the present embodiment, the five to nine magnetic disks 18 areaccommodated in the housing 10. However, the number of magnetic disks 18is not limited to this. In addition, a single magnetic disk 18 may beaccommodated in the housing 10.

In the housing 10, a plurality of magnetic heads 32 which record andreproduce information on and from the magnetic disks 18, and a headstack assembly (actuator) 22 which supports the magnetic heads 32, suchthat the magnetic heads 32 are movable with respect to the magneticdisks 18, are provided. The head stack assembly 22 comprises a rotatablebearing unit 28, a plurality of arms 30 extending from the bearing unit28, and a plurality of suspensions 34 extending from the arms 30,respectively. The magnetic heads 32 are supported on the distal ends ofthe suspensions 34, respectively.

Further, in the housing 10 are provided a voice coil motor (hereinafterreferred to as a VCM) 24 which rotates and positions the head stackassembly 22, a ramp load mechanism 25 which holds the magnetic heads 32at an unloading position that is away from the magnetic disks 18 whenthe magnetic heads 32 are moved to the outermost circumferences of themagnetic disks 18, and a board unit (first electrical component) 21 onwhich electronic components including a conversion connector (firstconnector) 70 a are mounted. The board unit 21 is formed of a flexibleprinted circuit (FPC). The FPC is electrically connected to a voice coilof the VCM 24 and the magnetic heads 32 via a relay FPC on the headstack assembly 22.

FIG. 3 is a perspective view of the base of the housing in a state inwhich most of the constituent elements are removed. FIG. 4 is aperspective view showing a rear surface side of the housing and acontrol circuit board.

As shown in FIG. 4, for example, a control circuit board 54 as a secondelectrical component is opposed to an outer surface of the bottom wall12 a of the base 12. The control circuit board 54 is screwed on thebottom wall 12 a. Electronic components, such as an IC, a coil, acapacitor, and a resistor, which are not shown in the figures, aremounted on the control circuit board 54. These electronic components andlines provided on the control circuit board 54 constitute a controllerwhich controls the operation of the HDD 10 and arithmetic processing.The controller controls the operation of the spindle motor 20, andcontrols the operation of the VCM 24 and the magnetic heads 32 via theboard unit 21. A second connector 70 b is mounted on an inner surface,that is, a surface facing the bottom wall 12 a, of the control circuitboard 54, and is electrically connected to the control circuit board 54.

As shown in FIG. 3 and FIG. 4, the HDD comprises a connection mechanism60 which electrically connects the first electrical component (boardunit 21) disposed inside the housing 10 and the second electricalcomponent (control circuit board 54) disposed outside the housing 10.The connection mechanism 60 includes a flexible printed circuit (FPC) 62provided on the bottom wall 12 a, the first connector 70 a electricallyconnected to the board unit 21, and the second connector 70 b connectedto the control circuit board 54. The board unit 21 is electricallyconnected to the control circuit board 54 via the first connector 70 a,the FPC 62, and the second connector 70 b.

FIG. 5 is a development view of the flexible printed circuitconstituting the connection mechanism. FIG. 6 is a perspective viewshowing the flexible printed circuit and a part of the housing. FIG. 7is a perspective view showing the flexible printed circuit and aconnector disposed in the housing. FIG. 8 is a sectional view of thehousing and the connection mechanism taken along line A-A of FIG. 3.

As shown in FIG. 5, the FPC 62 is formed into the form of a thin flatband and into the form of a film. The FPC 62 comprises a base insulatinglayer formed of an insulating synthetic resin, for example, polyimide, aconductive layer laid on the base insulating layer, and a coverinsulating layer laid on the base insulating layer and the conductivelayer. The conductive layer is formed of a conductive metallic material,for example, a copper material, and is patterned to form a plurality oflines L and a plurality of connection pads CP1 and CP2. The coverinsulating layer is formed of an insulating synthetic resin, forexample, polyimide, and covers the conductive layer and the baseinsulating layer except for the connection pads CP1 and CP2. Theconnection pads CP1 and CP2 are exposed at a first surface S1 of the FPC62. In the present embodiment, the first surface S1 of the FPC 62 is asurface formed by the cover insulating layer, and a second surface S2 onthe opposite side is a surface formed by the base insulating layer.

The FPC 62 comprises a first connection portion 64 a formed at one endportion in a longitudinal direction, a second connection portion 64 bformed at the other end portion in the longitudinal direction, and arelay portion 64 c located between the first connection portion 64 a andthe second connection portion 64 b. The first connection portion 64 a isformed into a rectangular shape. The first connection portion 64 a isprovided with a plurality of first connection pads CP1. The firstconnection pads CP1 are, for example, arranged in two lines. Each of thefirst connection pads CP1 is, for example, formed into a rectangularshape. Each of the lines extends in a direction orthogonal to thelongitudinal direction of the FPC 62, for example, in a width direction.In each of the lines, a plurality of first connection pads CP1, forexample, six first connection pads CP1, are arranged with a gaptherebetween. In addition, the two lines extend parallel to each otherwith a gap therebetween.

At least one first connection pad (first pad) of the first connectionpads CP1 has dimensions and a contact area which are greater than thoseof the other first connection pads. For example, the at least one firstconnection pad is formed to have a width greater than the width of theother first connection pads. According to the present embodiment, twofirst connection pads CP1A which are located at one end and the otherend of each of the lines are formed to have a width (for example, 1.2 to2 times) greater than the width of the other first connection pads CP1in the same line. The other first connection pads CP1 are formed to havethe same dimensions. Also, the first connection pads CP1A may have awidth equal to that of the other first connection pads CP1 and have alength greater than that of the other connection pads CP1.Alternatively, the first connection pads CP1A may have a width and alength which are greater than those of the other first connection padsCP1.

The first connection portion 64 a comprises one or more positioningholes 66 a as engagement portions for positioning. In the presentembodiment, the first connection portion 64 a comprises two positioningholes 66 a formed at both end portions in a width direction.

The second connection portion 64 b is formed into a rectangular shape.The second connection portion 64 b is provided with a plurality ofsecond connection pads CP2. Each of the second connection pads CP2 is,for example, formed into a rectangular shape. The second connection padsCP2 are, for example, arranged in two lines. Each of the lines extendsin the width direction of the FPC 62. In each of the lines, a pluralityof second connection pads, for example, six second connection pads, arearranged with a gap therebetween. In addition, the two lines extendparallel to each other with a gap therebetween.

At least one second connection pad (second pad) of the second connectionpads CP2 has dimensions which are greater than those of the other secondconnection pads, for example, a greater width. According to the presentembodiment, two second connection pads CP2A which are located at one endand the other end of each of the lines are formed to have a width (forexample, 1.2 to 2 times) greater than the width of the other secondconnection pads CP2 in the same line. The other second connection padsCP2 are formed to have the same dimensions. The second connection padsCP2 are connected to the corresponding first connection pads CP1 via thelines L of the FPC 62, respectively.

The second connection portion 64 b comprises one or more positioningholes 66 b for positioning. In the present embodiment, the secondconnection portion 64 b comprises two positioning holes 66 b formed atboth end portions in a width direction.

As shown in FIG. 6 and FIG. 7, a through-hole 74 in the form of a slitis provided at a predetermined position on the bottom wall 12 a. Thethrough-hole 74, for example, has the sectional shape of a long narrowrectangle, and is formed to have a length which is slightly greater thanthe width of the FPC 62 and a width which is slightly greater than thethickness of the FPC 62. The through-hole 74 is formed to penetrate thebottom wall 12 a, and opens at the inner surface and the outer surfaceof the bottom wall 12 a.

The bottom wall 12 a comprises a pair of bosses (positioning pins) 78 aprojected from the inner surface of the bottom wall in the vicinity ofthe through-hole 74. In addition, the bottom wall 12 a comprises a pairof bosses (positioning pins) 78 b projected from the outer surface ofthe bottom wall in the vicinity of the through-hole 74. The bosses 78 aand 78 b are, for example, formed into a cylindrical shape. The bosses78 a and 78 b may be formed integrally with the bottom wall 12 a, or maybe composed of separate pins fixed on the bottom wall 12 a.

The FPC 62 is inserted in the through-hole 74, and the relay portion 64c of the FPC 62 is located in the through-hole 74. The first connectionportion 64 a is bent to the inner surface side of the bottom wall 12 awith respect to the relay portion 64 c, and is located to face the innersurface of the bottom wall 12 a. In addition, the bosses 78 a are fittedin the pair of positioning holes 66 a of the first connection portion 64a, respectively. The first connection portion 64 a is thereby positionedand held on the inner surface of the bottom wall 12 a in a state inwhich the first connection pads CP1 face the inside of the housing 10.

The second connection portion 64 b is bent to the outer surface side ofthe bottom wall 12 a with respect to the relay portion 64 c, and islocated to face the outer surface of the bottom wall 12 a. In addition,the bosses 78 b are fitted in the pair of positioning holes 66 b of thesecond connection portion 64 b. The second connection portion 64 b isthereby positioned and held on the outer surface of the bottom wall 12 ain a state in which the second connection pads CP2 face the outside ofthe housing 10. In the present embodiment, the second connection portion64 b is bent in the same direction as the first connection portion 64 a.The second connection portion 64 b thereby faces the first connectionportion 64 a with the bottom wall 12 a interposed therebetween.

As shown in FIG. 8, a gap between the through-hole 74 of the bottom wall12 a and the relay portion 64 c of the FPC 62 is filled with a sealant65. The sealant 65 fills the gap between the through-hole 74 and therelay portion 64 c, thereby preventing a leak of gas from thethrough-hole 74 and fixing the relay portion 64 c on the bottom wall 12a.

As shown in FIG. 7 and FIG. 8, the second connector 70 b is, forexample, formed as a compression connector. The second connector 70 bcomprises a base 80 which is formed of an insulating material and issubstantially in the form of a rectangular parallelepiped, and aplurality of conductive connection terminals CT2 which are fixed on thebase 80. The connection terminals CT2 are formed by bending an elasticmetallic plate into a predetermined shape. The connection terminals CT2are arranged in a longitudinal direction of the base 80, for example, intwo lines. In each of the lines, a plurality of connection terminalsCT2, for example, six connection terminals CT2, are arranged with a gaptherebetween. In addition, the two lines extend parallel to each otherwith a gap therebetween. The number of connection terminals CT2, thepitch of arrangement, and the position where they are disposed are setin accordance with the above-described second connection pads CP2 of theFPC 62.

End portions of the connection terminals CT2 project from the base 80,are soldered at predetermined positions on the control circuit board 54,and are mechanically and electrically connected to the control circuitboard 54. The other end portions of the connection terminals CT2 projectfrom the base 80 in a direction opposite to the control circuit board54, that is, to the housing 10 side. The other end portions are bent tothe base 80 side at intermediate portions, and constitute contact makerswhich can elastically contact the connections pads of the FPC 62.

At least one connection terminal of the connection terminals CT2 areformed to have a width or a diameter which is greater than that of theother connection terminals CT2. According to the present embodiment, twoconnection terminals CT2A which are located at one end and the other endof each of the lines are formed to have a width (for example, 1.2 to 2times) greater than that of the other connection terminals CT2 in thesame line. The other connection terminals CT2 are formed to have thesame dimensions. The connection terminals CT2A, which are wide, areprovided to correspond to the second connection pads CP2A, which arewide, respectively.

As shown in FIG. 8, the control circuit board 54 is disposed to face theouter surface of the bottom wall 12 a and screwed on the bottom wall 12a, and the connection terminals CT2 of the second connector 70 b arethereby pressed on the corresponding second connection pads CP2,respectively. The connection terminals CT2 in an elastically deformedstate are thereby pressed on the second connection pads CP2, and areelectrically connected to the second connection pads CP2.

As shown in FIG. 8, the first connector 70 a has the same structure asthat of the second connector 70 b. That is, the first connector 70 acomprises a base 81 which is formed as a compression connector and whichis formed of an insulating material and is substantially in the form ofa rectangular parallelepiped, and a plurality of conductive connectionterminals CT1 which are fixed on the base 81. The connection terminalsCT1 are formed by bending an elastic metallic plate into a predeterminedshape. The connection terminals CT1 are arranged in a longitudinaldirection of the base 81, for example, in two lines. In each of thelines, a plurality of connection terminals CT1, for example, sixconnection terminals CT1, are arranged with a gap therebetween. Inaddition, the two lines extend parallel to each other with a gaptherebetween. The number of connection terminals CT1, the pitch ofarrangement, and the position where they are disposed are set inaccordance with the above-described first connection pads CP1 of the FPC62.

End portions of the connection terminals CT1 project from the base 81,are soldered at predetermined positions on the FPC constituting theboard unit 21, and are mechanically and electrically connected to theboard unit 21. The other end portions of the connection terminals CT1project from the base 81 in a direction opposite to the board unit 21,that is, to the bottom wall 12 a side. The other end portions are bentto the base 81 side at intermediate portions, and constitute contactmakers which can elastically contact the first connections pads CP1 ofthe FPC 62.

At least one connection terminal of the connection terminals CT1 areformed to have a width or a diameter which is greater than that of theother connection terminals CT1. According to the present embodiment, twoconnection terminals CT1A which are located at one end and the other endof each of the lines are formed to have a width (for example, 1.2 to 2times) greater than that of the other connection terminals CT1 in thesame line. The other connection terminals CT1 are formed to have thesame dimensions. The connection terminals CT1A, which are wide, areprovided to correspond to the first connection pads CP1A, which arewide, respectively.

As shown in FIG. 3 and FIG. 8, the first connector 70 a is disposed toface the first connection portion 64 a and the board unit 21 is screwedon the inner surface of the bottom wall 12 a, and the connectionterminals CT1 of the first connector 70 a are thereby pressed on thecorresponding first connection pads CP1, respectively. The connectionterminals CT1 in an elastically deformed state are thereby pressed onthe first connection pads CP1, and are electrically connected to thefirst connection pads CP1.

By means of the connection mechanism 60 having the above-describedstructure, the board unit 21 (first electrical component) disposedinside the housing 10 is electrically connected to the control circuitboard 54 (second electrical component) disposed outside the housing 10in a state in which the inside of the housing 10 is kept airtight.

According to the first embodiment having the above-described structure,by means of the connection mechanism 60 having a simple and low-pricedstructure comprising the FPC in the form of a sheet and the first andsecond connectors, an electrical component disposed inside the housing10 and an electrical component disposed outside the housing 10 can beelectrically connected to each other in a state in which the inside ofthe housing 10 is kept airtight. In addition, since at least one of theconnection pads of the FPC 62 is a wide connection pad, the connectionterminals CT1 of the first connector 70 a can be brought into contactwith the first connection pads CP1, even if the first connector 70 a isdisposed at a position shifted from a predetermined position withrespect to the first connection portion 64 a.

FIG. 9A shows a connection state in a case where the first connector 70a is disposed at a predetermined position. FIG. 9B shows a connectionstate in a case where the first connector 70 a is disposed at a positionshifted from the predetermined position. From these figures, it can beseen that the connection terminals CT1 of the first connector 70 a aresurely connected to the first connection pads CP1, respectively, in boththe case where the first connector 70 a is disposed at the predeterminedposition and the case where the first connector 70 a is disposed at theposition shifted from the predetermined position. In this manner, thefirst connector 70 a can be connected to the first connection portion 64a surely and stably, and an improvement in reliability can be made.Moreover, according to the present embodiment, the connection terminalsCT1A of the first connector 70 a, which correspond to the wide firstconnection pads CP1A, are formed to have a width or a diameter which isgreater than that of the other connection terminals CT1. Thus, theconnection terminals of the first connector 70 a can be connected to thefirst connection pads CP1 and CP1A more surely and stably.

The same is true of the connection between the second connection portion64 b of the FPC 62 and the second connector 70 b. Thus, the connectionterminals CT2 of the second connector 70 b can be connected to thesecond connection pads CP2 of the second connection portion 64 b surelyand stably, and the reliability of connection can be improved.

In addition, if the wide first connection pads CP1A or the wide secondconnection pads CP2A are used as connection pads for supplying power orconnection pads for grounding, greater current can be passed theretothan to the other connection pads.

In view of the foregoing, according to the first embodiment, theelectronic device, wherein electrical components can be connected morestably by virtue of a cheap structure, can be provided.

Various modified examples will be next described. In the modifiedexamples described hereinafter, the same portions as those of theabove-described first embodiment will be given the same referencenumerals, and their detailed description is simplified or omitted.Portions different from those of the first embodiment will be mainlydescribed in detail.

First Modified Example

FIG. 10 is a development view showing the flexible printed circuit (FPC)according to a first modified example. According to the first modifiedexample, in the FPC 62, semicircular cutouts 66C formed at side edges ofthe FPC 62, respectively, are used as engagement portions which engagewith the bosses of the housing.

If the cutouts 66 c are used as the engagement portions, the firstconnection portion 64 a and the second connection portion 64 b of theFPC 62 can be easily engaged with the bosses of the bottom wall, and thefirst connection portion 64 a and the second connection portion 64 b canbe positioned by the bosses.

Second Modified Example

FIG. 11 is a development view showing the flexible printed circuit (FPC)according to a second modified example. According to the second modifiedexample, the FPC 62 comprises the positioning holes 66 a formed at boththe end portions of the first connection portion 64 a, respectively, thepositioning holes 66 b formed at both the end portions of the secondconnection portion 64 b, respectively, four second holes 66 d formed atpositions adjacent to the positioning holes 66 a and 66 b, respectively,and slits 71 which are formed between the positioning holes and thesecond holes 66 d and which communicate with the second holes 66 d.

According to the FPC 62 having the above structure, for example, ifstress acts on the circumferences of the positioning holes 66 a and 66 bwhen the bosses are fitted in the positioning holes 66 a and 66 b, thisstress can escape to the second holes 66 d through the slits 71. Adeformation, a break, etc., in the FPC 62 due to stress thereby can beprevented.

Third Modified Example

FIG. 12 is a development view showing the flexible printed circuit (FPC)according to the third modified example. FIG. 13 is a plan view showinga state in which the FPC according to the third modified example isdisposed in the housing.

According to the third modified example, as shown in FIG. 12, the FPC 62comprises the positioning holes 66 a and 66 b, the second holes 66 d,and the slits 71 as in the case of the above-described second modifiedexample. Moreover, the FPC 62 comprises a pair of first slits 80 aformed along a boundary between the first connection portion 64 a andthe relay portion 64 c, and a pair of second slits 80 b formed along aboundary between the second connection portion 64 b and the relayportion 64 c. The first slits 80 a and the second slits 80 b open at theside edges of the FPC 62, respectively. Since the first slits 80 a andthe second slits 80 b are provided, both end portions in a widthdirection of the relay portion 64 c constitute bendable tongue portions82, respectively.

As shown in FIG. 13, when the FPC 62 having the above-describedstructure is attached to the bottom wall 12 a of the housing, the relayportion 64 c and the tongue portions 82 are inserted in the through-hole74 of the bottom wall 12 a in a state in which the pair of tongueportions 82 are bent to face a central portion in the width direction ofthe relay portion 64 c. The pair of tongue portions 82 in an elasticallydeformed state press on the inner surface of the through-hole 74, andcause the relay portion 64 c to press on the inner surface of thethrough-hole 74 on the opposite side. The relay portion 64 c thereby canbe positioned and held at a predetermined position in the through-hole74.

Fourth Modified Example

FIG. 14 is a plan view showing the through-hole of the housing accordingto a fourth modified example. As shown in this figure, according to thefourth modified example, the through-hole 74 is formed into the shape ofa long narrow slit, and moreover, both end portions in a longitudinaldirection of the through-hole 74 are formed into an arc shape. Thethrough-hole 74 is formed, such that the length between the apex of oneedge of the arc shape and the apex of the other edge of the arc shape issubstantially equal to the width of the FPC 62. When the FPC 62 isinserted in the above through-hole 74, the FPC 62 is positioned at aposition where both the side edges of the FPC 62 contact the apexes ofthe edges of the through-hole 74, respectively.

Fifth Modified Example

FIG. 15 is a plan view showing the through-hole of the housing accordingto a fifth modified example. As shown in this figure, according to thefifth modified example, the through-hole 74 is formed into the shape ofa long narrow slit, and has the sectional shape of a trapezoid. Thethrough-hole 74 is formed, such that the length of a portion as the baseof the trapezoid is substantially equal to the width of the FPC 62. Whenthe FPC 62 is inserted in the above through-hole 74, the FPC 62 ispositioned at a position on the base side of the trapezoid in thethrough-hole 74.

Sixth Modified Example

FIG. 16A, FIG. 16B, and FIG. 16C are sectional and plan views showingthe through-hole of the housing according to a sixth modified example.As shown in these figures, according to the sixth modified example, thethrough-hole 74 formed to penetrate the bottom wall 12 a is a steppedthrough-hole comprising a major diameter hole 74 a and a minor diameterhole 74 b. The major diameter hole 74 a extends from the inner surfaceof the bottom wall 12 a to the vicinity of the bottom wall 12 a. Theminor diameter hole 74 b extends from the outer surface of the bottomwall 12 a to the major diameter hole 74 a, and communicates with themajor diameter hole 74 a. An end portion of the major diameter hole 74 awhich communicates with the minor diameter hole 74 b is formed into apointed or tapered shape.

The sectional shape of the major diameter hole 74 a is formed into aslit shape having a first width WT1. Moreover, both ends in alongitudinal direction of the major diameter hole 74 a are formed intoan arc shape. The major diameter hole 74 a is formed, such that thelength between the apex of one edge of the arc shape and the apex of theother edge of the arc shape is substantially equal to a first width WP1of the FPC 62.

The sectional shape of the minor diameter hole 74 b is formed into aslit shape having a second width WT2 less than the above first widthWT1. Moreover, both ends in a longitudinal direction of the minordiameter hole 74 b are formed into an arc shape. The minor diameter hole74 b is formed, such that the length between the apex of one edge of thearc shape and the apex of the other edge of the arc shape issubstantially equal to a second width WP2 of the FPC 62.

As is schematically shown in FIG. 16B, the FPC 62 is formed to have thefirst width WP1 from an intermediate portion of the relay portion to oneend of the FPC 62, and have the second width WP2 from the intermediateportion of the relay portion to the other end of the FPC 62. The secondwidth WP2 is less than the first width WP1.

As shown in FIG. 16A, FIG. 16B, and FIG. 16C, the FPC 62 is inserted inthe through-hole 74, a portion having the first width is positioned at aposition where both the side edges contact the apexes of the edges ofthe major diameter hole 74 a, and a portion having the second width ispositioned at a position where both the side edges contact the apexes ofthe edges of the minor diameter hole 74 b. In this manner, since thethrough-hole 74 having the above shape is provided, the FPC 62 can bepositioned at a predetermined position in the through-hole 74, and adisplacement, a flexure, etc., of the FPC 62 can be prevented.

Seventh Modified Example

FIG. 17 is a plan view showing the connection portions of the flexibleprinted circuit (FPC) according to the seventh modified example. Thestructure of the first connection portion 64 a will be described as arepresentative of the connection portions of the FPC. As shown in thisfigure, according to the seventh modified example, the first connectionpads CP1 provided on the first connection portion 64 a of the FPC 62 arearranged in a so-called zigzag pattern.

To be specific, the first connection pads CP1 are, for example, arrangedin four lines. Each of the first connection pads CP1 is, for example,formed into a rectangular shape. Each of the lines extends in adirection orthogonal to the longitudinal direction of the FPC 62, forexample, in the width direction. In each of the lines, the plurality offirst connection pads CP1, for example, eight or seven first connectionpads CP1, are arranged with a gap therebetween. The four lines extendparallel to each other with a gap therebetween in the longitudinaldirection of the FPC 62.

When the above four lines are regarded as a first line, a second line, athird line, and a fourth line from one end side of the first connectionportion 64 a, the eight first connection pads CP1 constituting the firstline are disposed at positions shifted in the width direction of the FPC62, respectively, with respect to the seven first connection pads CP1constituting the second line. In addition, the seven first connectionpads CP1 constituting the third line are disposed at positions shiftedin the width direction of the FPC 62, respectively, with respect to theeight first connection pads CP1 constituting the fourth line.

In the present modified example, the two first connection pads CP1Alocated at one end and the other end of the first line, and the twofirst connection pads CP1A located at one end and the other end of thefourth line have a width greater than that of the other first connectionpads CP1 constituting each of the lines. That is, the surface area(contact area) of the first connection pads CP1A is greater than that ofthe other first connection pads CP1. Further, the second connectionportions of the FPC 62 also have the same structure as that of theabove-described first connection portion 64 a.

As described above, according to the seventh modified example, the FPC,in which the connection pads are arranged in a zigzag pattern, can beobtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. Various aspects of the invention can also be extracted fromany appropriate combination of constituent elements disclosed in theembodiment. For example, some of the constituent elements disclosed inthe embodiment may be deleted. Furthermore, the constituent elementsdescribed in different embodiments may be arbitrarily combined. Theaccompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of theinventions.

For example, the first connector and the second connector are notlimited to compression connectors, and other connectors can be adopted.The first connection portion and the second connection portion of theFPC are not necessarily bent in the same direction, and may be bent indirections opposite to each other. The number of disposed connectionpads and the shape of the connection pads are not limited to those inthe above-described embodiment, and can be changed in various ways. Inaddition, the electronic device according to the present invention isnot limited to a disk drive, and can be applied to other electronicdevices.

What is claimed is:
 1. An electronic device comprising: a housingcomprising a through-hole; a flexible printed circuit comprising a firstconnection portion provided with a plurality of first connection padsand a second connection portion provided with a plurality of secondconnection pads, the flexible printed circuit being inserted in thethrough-hole, the first connection portion being disposed on an innerside of the housing, and the second connection portion being disposed onan outer side of the housing; a sealant filled in the through-hole toseal the through-hole and preventing a leak of gas from thethrough-hole; a first electrical component in the housing; and a firstconnector in the housing connected to the first electrical component,the first connector comprising a plurality of connection terminals whichcontact the first connection pads, respectively, wherein a first pad ofthe first connection pads is greater in size than other first connectionpads.
 2. The electronic device of claim 1, wherein a connection terminalof the first connection terminals, which contacts the first pad,includes a greater width or a greater diameter than a width or adiameter of other first connection terminals.
 3. The electronic deviceof claim 2, further comprising: a second electrical component providedoutside the housing; and a second connector connected to the secondelectrical component, wherein the second connector comprises a pluralityof connection terminals which contact the second connection pads,respectively, and a second pad of the second connection pads is greaterin size than other second connection pads.
 4. The electronic device ofclaim 3, wherein a connection terminal of the connection terminals,which contacts the second pad of the second connection pads, includes agreater width or a greater diameter than a width or diameter of otherconnection terminals.
 5. The electronic device of claim 2, furthercomprising: a disk-shaped recording medium in the housing; and a headwhich records data on the recording medium, and the gas has a lowerdensity than a density of air and the gas is sealed in the housing. 6.The electronic device of claim 1, wherein the first pad of the firstconnection pads is a connection pad for supplying power or forgrounding.
 7. The electronic device of claim 1, wherein the firstconnection pads are arranged in a plurality of lines, and the first padof the first connection pads is located at one end or the other end ofeach of the lines.
 8. The electronic device of claim 1, wherein thehousing comprises a pair of projections, and the first connectionportion comprises engagement portions fitted to the projections.
 9. Theelectronic device of claim 1, further comprising: a second electricalcomponent provided outside the housing; and a second connector connectedto the second electrical component, wherein the second connectorcomprises a plurality of connection terminals which contact the secondconnection pads, respectively, and a second pad of the second connectionpads is greater in size than other second connection pads.
 10. Theelectronic device of claim 9, wherein a connection terminal of theconnection terminals, which contacts the second pad of the secondconnection pads, includes a greater width or a greater diameter than awidth or diameter of other connection terminals.
 11. The electronicdevice of claim 9, wherein the second connection pads comprise aplurality of the second pads.
 12. The electronic device of claim 1,further comprising: a disk-shaped recording medium in the housing; and ahead which records data on the recording medium, wherein the gas havinga lower density than a density of air is sealed in the housing.
 13. Theelectronic device of claim 1, wherein the first connection pads comprisea plurality of the first pads.
 14. The electronic device of claim 1,wherein the first connector comprises a base, and the connectionterminals project from the base toward the first connection portion anddirectly contact the first connection pads, respectively.
 15. Theelectronic device of claim 1, wherein the flexible printed circuit isformed into a flat band and into a film.
 16. The electronic device ofclaim 1, wherein the flexible printed circuit comprises a baseinsulating layer of an insulating synthetic resin, a conductive layerlaid on the base insulating layer, and a cover insulating layer laid onthe base insulating layer and the conductive layer.